The invention relates generally to multilayer pads and methods of manufacture such as are disclosed in our earlier Woods et al U.S. Pat. No. 5,230,119, titled “Multilayer Laminated Pad;” U.S. Pat. No. 5,507,906 (now U.S. Re. 36,601), titled “Method for Making Multilayer Pad;” U.S. Pat. No. 5,771,524, titled “Disposable Pad;” and U.S. Pat. No. 6,493,898, titled “Laminated pads and methods of manufacture employing mechanically folded handles,” the entire disclosures of which are hereby expressly incorporated by reference; as well as Zygmont U.S. Pat. No. 6,044,515, the entire disclosure of which is hereby expressly incorporated by reference.
The pads disclosed in our earlier patents generally are manufactured by initially forming a two- or three-layer composite laminated sheet using adhesive or other attachment to combine base pad forming material, impervious barrier layer forming material, and handle forming material. The base pad forming material, barrier layer forming material and handle forming material are provided as respective webs of material from supply rolls, the webs each having a predetermined width (typically the same width for all three webs in the pads disclosed in U.S. Pat. No. 5,230,119; U.S. Pat. No. 5,507,906; U.S. Re. 36,601 and U.S. Pat. No. 5,771,524), with lengths depending on the roll size. U.S. Pat. No. 5,230,119; U.S. Pat. No. 5,507,906 and U.S. Re. 36,601 generally disclose pads which have what may be referred to as “L”-shaped handles. U.S. Pat. No. 5,771,524 generally discloses pads which have handles that may be referred to as “wings”. U.S. Pat. No. 6,493,898 generally discloses pads which have what may be referred to as “folded” handles.
In the pads disclosed in U.S. Pat. No. 5,230,119; U.S. Pat. No. 5,507,906 and U.S. Re. 36,601 (“L”-shaped handles), and U.S. Pat. No. 5,771,524 (“wings”), the exemplary adhesive attaching the web of base pad forming material and the web of barrier layer forming material to each other is applied as a full coating, such that these two web layers are continuously adhered to each other along their entire widths. However, the adhesive which joins the web of barrier layer forming material to the web of handle forming material is applied in longitudinal strips, which may be referred to as “zone coating.” A cutter is then used to cut through all three layers of the laminated sheets to produce individual multilayer pads. The cutter is aligned with reference to the adhesive strips securing the handle forming material to the barrier forming material, as well as with reference to uncoated areas between the adhesive strips, such that, in each of the resulting pads, a portion of the handle forming material layer is over an adhesive strip resulting in an adhered segment of the handle, and another portion (or portions) of the handle forming material layer within the shape of the cutter is over an uncoated area resulting in a free or graspable portion of the handle. The resultant graspable handle portion lies flat against the barrier layer prior to initial use, and pivots up for use.
U.S. Pat. No. 6,493,898 (“folded” handles) discloses the manufacture of similar pads, while avoiding the need for zone coating to define adhered handle segments. Rather, the handle forming material is mechanically folded, employing a pleating/folding machine, prior to being adhered to the barrier layer. As alternatives, adhesive is applied to the barrier layer, or to the underside of the handle forming material subsequent to folding, or to the underside of the handle forming material prior to folding.
Although several prior art patents, for example Woods et al U.S. Pat. No. 5,771,524, include general suggestions that layers may be fused employing an ultrasonic bonding process without the use of adhesive, as a practical matter specific processes and resultant pads are not disclosed. Rather, a characteristic of actual commercial embodiments (for example pads with “L”-shaped handles as disclosed in U.S. Pat. No. 5,230,119) is that the various layers are joined employing adhesives.